The Sudd Wetland in South Sudan is among the largest freshwater ecosystems in the world and is of significant ecological, hydrological, and socio-economic importance. This vast wetland complex supports exceptional biodiversity, including numerous endemic, migratory, and endangered species, and plays a critical role in regional climate regulation, water purification, and flood mitigation. It also sustains the livelihoods of thousands of people through fisheries, pastoralism, agriculture, and cultural heritage practices deeply rooted in the landscape. As part of the government’s commitment to conservation and sustainable development, and in collaboration with UNESCO’s Man and the Biosphere (MAB) Programme, the government of South Sudan aims to nominate the Sudd Wetlands as a UNESCO Biosphere Reserve. Designating the Sudd as a Biosphere Reserve is vital for promoting integrated and inclusive management of this globally significant ecosystem. It will strengthen national and international cooperation for biodiversity conservation, enhance climate resilience, and support sustainable livelihoods of the concerned communities in the vast landscape through science-based planning, ecosystem-based adaptation, and the incorporation of indigenous knowledge systems. The designation will also raise the profile of South Sudan in global conservation efforts and unlock opportunities for technical assistance, research collaboration, and sustainable financing mechanisms.  A draft Nomination Dossier was developed in 2023; however, it requires substantive revisions based on UNESCO MAB Secretariat feedback, including incorporation of additional data, stakeholder inputs, and the development of a comprehensive Management Plan. Biosphere Reserves are areas designated under UNESCO’s Man and the Biosphere (MAB) Programme that aim to reconcile biodiversity conservation and sustainable use of natural resources. In response to identified gaps and to advance the successful nomination and sustainable management of the proposed Biosphere Reserve, a comprehensive and participatory process is required. This includes preparing a well-structured Nomination Dossier and a robust, long-term Management Plan that addresses ecological, social, and governance dimensions.